If you look in the lower right corner of the XP Taskbar, you should see the system time. This system time is displayed as a convenience to you, and it is also a vital part of the computer's day-to-day operation. Even if you choose not to have the system time on display, the time still controls a wide variety of functions that go on underneath the hood.
If you hover your mouse pointer over the system time display, you'll also see the system date displayed as a ScreenTip. But as mentioned, this is the default behavior, and you can disable the display of system time by right-clicking the Taskbar, choosing Properties, and then unchecking the "Show the Clock" check box in the Start Menu and Taskbar Properties dialog box.
As with previous versions of Windows, you can always set the time and date manually using the Time and Date Properties dialog box. But now with Windows XP, you don't have to bother. If you have a connection to the Internet, you can tell XP to use an Internet time server instead.
Automatic time and date synchronization. Cool. Here's how:
Two caveats here. First, you might not successfully update the time to the Internet time servers if your system date is incorrectly set. Second, not all corporate firewalls (such as the one I was behind when I captured the screenshot) will allow this type of communication to Internet time servers. If you're trying to use this feature from within a corporate network, you might just have to configure time and date manually if your domain has an incorrect time.
If you're experiencing difficulty on a personal network, check the settings of your firewall. The Microsoft Windows Firewall should allow traffic to network time protocol servers.
If you don't see the clock, right-click the Taskbar, choose Properties, and then uncheck the "Show the Clock" check box in the Start Menu and Taskbar Properties dialog box.